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HARD WICKE 'S S CIENCE - G OS SIP. 



and its votaries cannot stand a strict scientific scrutiny, 

 unless when entirely shielded by, and made sub- 

 servient to, true Ornithology. We are told that Mr. 



has a vei7 fine Oological collection. What 



does that mean ? In nine cases out of ten it simply 

 signifies that that scientifically inclined gentleman has 

 accumulated a large quantity of birds' eggs, which he 

 has blown, stuck on cords, and ranged in his cabinet, 

 where visitors can see and admire them. No one can 

 deny that the effect is truly very pretty, but the spirit 

 of the work is not so admirable ; it is exactly similar 

 to the motives a school-boy has to collect postage- 

 stamps, or buttons, or pieces of broken crockery; 

 there is not a whit more true science in it than there 

 would be in making a collection of birds' legs or tails. 

 And at what cost is this fancy work carried on ? At 

 the sacrifice of hundreds of little songsters, to say 

 nothing of the larger birds ; at the cost of the local 

 extermination of the rarer species, by the depopulation 

 of the field, the garden, the orchard, and the wood- 

 lands of their most beautiful inhabitants, and of the 

 consequent multiplication of a hundred forms of insect 

 vermin. Take a moderate-sized collection of say lOo 

 species, with an average of three eggs of a kind ; add 

 to this a hundred for eggs lost, owing to the unwilling- 

 ness of the parent birds to return to a disturbed nest ; 

 add fifty for eggs broken or otherwise lost in prepara- 

 tion, and another hundred for companion eggs which 

 have been transferred to another collection, and you 

 have the equivalent of at least 500 birds slaughtered 

 for m.ere amusement on a British holiday. Surely 

 there is no utility in a collection of eggs, except when 

 it constitutes a portion of a thorough ornithological 

 collection, where the bird, its nest, and eggs, are 

 placed in juxtaposition for scientific comparison and 

 investigation : then indeed it fills an important 

 position, for the history of a bird cannot be looked 

 upon as complete until its habits of nidification and 

 its Oology (if the term musthe employed) ai-e known. 

 If egg-collecting as egg-collecting would be dropped 

 by (so-called) naturalists, and the general rule laid 

 down never to take an egg of whose parent bird the 

 collector does not possess a specimen or a reasonable 

 hope of obtaining one, it seems to me that a per- 

 ceptible check would be given to this wholesale, 

 useless, and cruel, but deplorably popular, method of 

 waging war against some of our best friends. — IV. T. 

 Van Dyck, Biyrout, Syria. 



Tadpoles. — As I have several times kept tadpoles, 

 I can inform your correspondent of the plan I have 

 found to succeed, though I am not thoroughly ac- 

 quainted with their history. He is probably aware 

 that it is now too late in the year to get any young 

 tadpoles or spawn. The spawn can be found in great 

 abundance at the edges of ponds in the early spring. 

 The young tadpoles should be kept in a wide, shallow 

 vessel, with a layer of gravel, earth, or sand at the 

 bottom, and some water- weeds, such as you will find 

 in the pond where they came from. The weeds 

 serve both to keep the water sweet and for food for 

 the tadpoles ; for at the beginning of their career 

 they are entirely herbivorous. You should get two or 

 three kinds of weed, for they do not like every sort. 

 But they seem to be veiy fond of the green slime 

 generally to be found in ponds, and I take care to let 

 mine have a pretty constant supply. The gravel 

 sei-ves to root the weeds, and I think helps to keep the 

 water pure. In a short time (perhaps two or three 

 weeks) they begin to become carnivorous, and must 

 have a tiny piece of lean meat given them oc- 

 casionally. In the wild state they doubtless supply 

 themselves with insects. If animal food is not 

 supplied, they do not develop at the proper time, and 



will continue in nearly the same state for weeks ; and 

 finally begin to devour one another. They do not 

 seem to mind whether the meat is raw or cooked, but 

 prefer it tender. A little piece the size of a three- 

 penny bit will feast a dozen tadpoles for perhaps a 

 day or two. It is most interesting to watch them 

 wrestling with the meat and struggling with each 

 other to get at it. They are as eager and voracious 

 as young kittens. As soon as they have four legs, 

 they begin to want to come out into the air occa- 

 sionally, and you must make a shelving bank, of 

 stones or a tile, where they can climb out of the 

 water easily. The gills are now giving place to lungs. 

 If they cannot easily get out to take an airing, they 

 will die, and the other younger tadpoles will act the 

 part of cannibals, ^^'^len they have begun to sit out 

 in the air, it is surprising how fast the tail is absorbed. 

 A single day will make a perceptible difference. 

 When it is nearly gone they begin to hop ; and it is 

 as well, when they reach this stage, to keep them out 

 of doors, putting the vessel (a pie-dish if you please) 

 on a level with the ground, so that they can come 

 back to the water if they wish. I give mine a change 

 of water occasionally ; but if there were more water 

 and weeds in proportion to the number of tadpoles, it 

 probably would not be necessary. — R.A. 



AQUARiUM-KEEriNG. — Ihavejust seen your corre- 

 spondent "P.E.C.'s " query (July number) ; and think- 

 ing some notes on my own experience might not be un- 

 interesting, I send them for what they may be worth. 

 My aquaria consist of a rectangular one, about 2 ft. 

 by I ft. 4 in., flanked on either side by a small bell- 

 glass about 9 in. in diameter. The centre aquarium 

 has a fountain and waste-pipe. I have also fixed 

 permanent siphons of fine glass tubing from it to each 

 of the side-glasses, so that I can at any time, by 

 drawing the water off from one of these, establish a 

 stream of water right through. The fountain does 

 not, I believe, meet with much favour from those who 

 keep aquaria upon purely scientific principles, but it 

 adds so much to the beauty of one, that I should ad- 

 vise all keepers of aquaria to introduce one. Mine is 

 simply a tank on the top of a bookshelf, in one corner 

 of the room, from which I have a kw yards of tubing 

 (India-rubber), passing through a metal pipe fixed to 

 the bottom of the aquarium. The mouthpiece is a 

 piece of glass tube, heated in a gas-jet, and drawn to 

 a fine point. It throws a jet about 3 ft. in height, 

 and passes little more than a gallon of water per 

 hour. The waste-pipe conducts the water to a pitcher 

 that stands behind the window-curtain, and all that 

 is necessary is to empty the water back into the cis- 

 tern some three or four times a day. The aquarium 

 is further embellished with a strip of virgin cork, 

 about 3 in. in width, running round the back and 

 ends, and just touching the top of the water. On 

 these I grow various kinds of moss and ferns, the 

 spray from the fountain seeming to suit them very 

 well. This, however, is only a recent addition, most 

 of the ferns having been planted this year. And now 

 for the contents of the aquaria : the bottom is co- 

 vered with sand and broken spar, and I have some 

 plants of valisneria in pots, the pots being concealed 

 in the sand. I have also some plants of water star- 

 wort and anacharis. The latter sorts do not, however, 

 do well in any place where there are fish, — at least that 

 is my experience. If grown without fish, or where 

 there are only very small ones, they will thrive very 

 well. I have tried Stratiotes aloides twice, but find the 

 snails are too fond of it ; they eat the plants away. 

 For fish, I have one goldfish, one tench, one ruffe, 

 two perch, and minnows and sticklebacks. Roach 

 I find not easy to keep, as sooner or later they are 



